The 8.2-kilometer river, said to be the longest navigable underground river in the world, winds its way underneath a mountain range, through the St. Paul Underground River Cave, and then goes out into the South China Sea. The journey through the cave system alone is 24 kilometers long.

The entire area where the Underground River is located is actually a national park and a model of biodiversity. More than 800 plant species, including almost 300 trees, 195 bird species, 30 mammals, 19 reptiles, and eight bat species call this area home.

These include at least 295 trees dominated by the dipterocarp species. In the lowland forest, large trees such as the Dao, Ipil, Dita, Amugis, and Apitong are common.

Fauna

Birds comprise the largest group of vertebrates found in the park. Of the 252 bird species known to occur in Palawan, a total of 165 species of birds were recorded in the park. This represents 67% of the total birds and all of the 15 endemic bird species of Palawan.

There are also some 30 mammal & 19 species of reptiles species that have been recorded. Most often observed in the forest canopy and along the shoreline feeding during low tide is the long-tailed macaque, the only primate found in the area.

Puerto Princesa Underground River Facts

The river is 8.2km long and flows underground through natural rock formations such as caves, stalactites, and stalagmites.

Only 4.3km of this are easily traveled by tourists. If tourists wish to travel the other 3.9km they have to obtain a special permit. In some of this 3.9km it is possible to wade in the river.

Some of the rock formations look similar to objects and images such as a horse, cacao fruit, a mushroom and the holy family.

One of the rock formations in the cavern that the river flows through looks like a naked lady.

Geologists and environmentalists discovered a second floor to the river in 2010. This led them to believe that there are waterfalls in the cave as well.

The lower half of the river has brackish water, which means it has more salt than fresh water, but not enough to be considered salt water.

The monkeys in Puerto Princesa Subterranean River National Park are so used to being fed by people that they will now grab food from visitors.

About Puerto Princesa Underground River

Travel by boat, through a massive cave on the longest underground river in the world.
Declared by UNESCO as a World Heritage Site.
See hundreds of bats, (close your mouth when looking up at the bats) giant monitor lizards, monkeys, python, sea snakes and other wildlife. An ECO-TOURISM adventure.